Terminals may be divided into mobile/portable terminals and stationary terminals according to mobility. Also, the mobile terminals may be classified into handheld types and vehicle mount types according to whether or not a user can directly carry.
Mobile terminals have become increasingly more functional. Examples of such functions include data and voice communications, capturing images and video via a camera, recording audio, playing music files via a speaker system, and displaying images and video on a display unit. Some mobile terminals include additional functionality which supports electronic game playing, while other terminals are configured as multimedia players. Specifically, in recent time, mobile terminals can receive broadcast and multicast signals to allow viewing of video or television programs.
As it becomes multifunctional, a mobile terminal can be allowed to capture still images or moving images, play music or video files, play games, receive broadcast and the like, so as to be implemented as an integrated multimedia player.
Efforts are ongoing to support and increase the functionality of mobile terminals. Such efforts include software and hardware improvements, as well as changes and improvements in the structural components.
In addition to the above attempts, wireless communication systems using LTE communication technologies have recently been commercialized to provide various services. Also, in the future, it is expected that a wireless communication system using 5G communication technology will be commercialized to provide various services. In this regard, a harmonic distortion signal is generated in a (frequency) up-converter (or down-converter) that converts a baseband signal or an intermediate frequency (IF) signal to an RF frequency signal to degrade performance of a communication system.
In this connection, a harmonic distortion phenomenon in the above-described up-converter is particularly remarkable in a multimode/multiband transmitting part. Recently, according to the tendency that communication systems are merged to a mobile terminal, the harmonic distortion phenomenon may increase. Therefore, such a multimode/multiband transmitting part needs to utilize a harmonic elimination structure to increase linearity in a specific operation mode.
In this connection, since a higher division ratio, i.e. a higher VCO frequency to be used, is required, such a structure may be restricted to a specific band (frequencies).